Knee prosthesis



FIG. 1 is a perspective view of a knee prosthesis showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a cross-sectional view taken along line VI--VI of FIG. 2.

FIG. 7 is a side elevational view looking from the right side in FIG. 1; and

FIG. 8 is a side elevational view looking from the left side in FIG. 1. 

The ornamental design for a knee prosthesis, as shown and described. 